AuldLangSyne 2.0

"Unknown friend response from server" is just a generic error message that's shown any time there was an error related to your friends list that doesn't have its own error message.

The other one is obvious, and you can easily reproduce it by creating an alt, adding it to your friends list on another character, then deleting the alt, and logging in. You should get the "Friend removed because the character no longer exists" message.

If you're getting them repeatedly though, and your friends list hasn't changed, there may be old names stuck in your saved variables that AuldLangSyne is trying to sync. You can either delete the saved variables file altogether (this will wipe out your friend/guild/ignore/player notes too) or just clean out the sync list.

Cheads, I get exactly the same errors as you in post #322, 15 in total according to Buggrabber and Bugsack.
It was one of my favorite addons especially due to the friends list syncing.
I have it on multiple computers and since patch 3.0.2 they all have exactly the same 15 errors.
Fingers crossed for a WoW 3.0.2+ update soon as I've searched and nothing fits to take its place (all in one).

Cheads, I get exactly the same errors as you in post #322, 15 in total according to Buggrabber and Bugsack.
It was one of my favorite addons especially due to the friends list syncing.
I have it on multiple computers and since patch 3.0.2 they all have exactly the same 15 errors.
Fingers crossed for a WoW 3.0.2+ update soon as I've searched and nothing fits to take its place (all in one).

Works fine now, the directory structure seemed to have changed at some point and as mentioned above there were double entries, deleted all copies of it, re-installed, no errors anymore, glad it still works, props to the author!

as you can see, the path in the error looks like:
LibBabble-Class-3.0\LibBabble-3.0.lua
which means that ALS was only the addon providing the core part of Babble-3.0.
This does not mean it's the one producing the error, especialy since I don't think ALS uses LibBabble-Quest-3.0 at all. So you'll have to find the addon that's causing the error and if the code in it is still functional with the current WoW version find someone to update LibBabble-Quest-3.0.